A gas-fired power generation system and power generation method utilizing efficient coupling of renewable energy

Abstract

The present invention provides a gas-fired power generation system and power generation method that utilizes efficient coupling of renewable energy. The gas-fired power generation system comprises: a renewable energy supply unit, a heat storage and exchange unit, a fuel gas supply unit, and a power generation unit. The heat storage and exchange unit stores heat from the renewable energy and exchanges heat with the fuel gas supply unit and / or the power generation unit. The fuel gas supply unit produces and stores fuel gas using renewable energy. The power generation unit comprises a SOFC cell and an induction coil. The SOFC cell receives the fuel gas and reacts to generate electricity. The induction coil is arranged around the SOFC cell and, at least when the SOFC cell is activated, supplies power to the induction coil, causing the SOFC cell to quickly heat up and start. This system can improve energy utilization efficiency and enhance the stability and continuity of the system's external power supply, thereby meeting future demands for efficient utilization of renewable and clean energy.

Description

Technical Field

[0001] The present invention relates to the field of clean energy technology, and in particular to a gas power generation system and a power generation method utilizing efficient coupling of renewable energy. Background Art

[0002] Currently, clean energy utilization systems have become a key research focus in the energy sector, particularly in the development and utilization of renewable energy sources such as solar energy and hydrogen. Combining green hydrogen technology with the photovoltaic industry is an effective solution and a key step in achieving carbon neutrality. Solar energy fundamentally reduces carbon emissions and provides clean energy in the form of green hydrogen. As a new type of energy storage, it can address the intermittent nature of renewable energy. However, existing clean energy systems still have numerous shortcomings in terms of energy efficiency, system stability, and energy storage conversion. For example, some systems experience significant heat losses during the conversion of high-temperature thermal energy, failing to fully utilize thermal resources and resulting in low overall energy efficiency. Furthermore, some power generation and energy storage systems struggle to respond quickly to grid peaks or solar power shortages, impacting the system's ability to provide continuous power. Furthermore, the molten salt heat exchange efficiency of existing systems is generally low, failing to fully utilize the thermal storage potential of molten salt. These issues severely restrict the performance and reliability of clean energy utilization systems.

[0003] Invention CN116111131A discloses an integrated power generation and energy storage system and operating method that integrates molten salt heat storage and exchange with RSOC. The system includes a SOFC power generation unit, a SOEC hydrogen production unit, and a molten salt heat storage and exchange unit. During low-power grid demand, the SOFC power generation unit operates at minimum load. The SOEC power generation unit utilizes excess power from the grid and heat stored in the molten salt heat storage and exchange system to electrolyze water vapor to generate hydrogen and oxygen, which are then stored. When the grid is experiencing peak demand, the SOEC hydrogen production unit operates at minimum load, and the SOFC power generation unit delivers power to the grid. Simultaneously, the heat released is stored in the molten salt heat storage and exchange system for use in preheating fuel gas during hydrogen production. This invention primarily relies on the difference in peak and valley electricity prices on the grid to achieve energy utilization. It does not fully utilize clean energy sources such as solar energy, making it difficult to completely break away from dependence on traditional energy sources.

[0004] Invention CN118031431A discloses a hydrogen production, power generation, and heating system based on a reversible solid oxide cell (SOFC) and a fixed solar field. In this heating system, cold molten salt is pumped into a solar collector system to generate hot molten salt, which is then stored in a hot molten salt storage tank. The hot salt in the hot molten salt storage tank is then pumped to a first heat exchanger for heat exchange with water. The resulting high-temperature water vapor enters a second heat exchanger for heat exchange, producing high-temperature hydrogen and high-temperature oxygen. The SOFC then enters an O2 storage tank, and the hydrogen enters a compressor and then an H2 storage tank. The oxygen and hydrogen are used by the SOFC for peak power generation. The system also produces hydrogen and generates electricity, while also providing district heating. This invention combines a fixed solar field, a solid oxide fuel cell (SOFC), a solid oxide electrolyzer, and both the Kalina cycle and the organic Rankine cycle (ORC). It effectively utilizes renewable resources, solar energy and water, to produce green hydrogen, while simultaneously storing the hydrogen and using it for power generation and heating. This invention does not address the issues of high SOFC startup temperature and long startup time, the difficulty in quickly starting the SOFC to provide supplementary power when monitoring emergencies such as peak power consumption, and the failure to fully collect and utilize the system's waste heat and exhaust gas, resulting in a more efficient use of the clean energy of the solar field.

[0005] Therefore, how to improve energy utilization efficiency, enhance the stability and sustainability of the power supply system, and provide clean energy utilization methods and continuous power generation systems and methods that meet the efficient utilization of renewable energy in the future is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In response to the defects in the above-mentioned prior art, the present invention provides a gas-fired power generation system and power generation method that utilizes efficient coupling of renewable energy. Through the coordinated cooperation of multiple power generation equipment, energy storage equipment, heat exchange equipment, etc., it intelligently and efficiently solves the problems that renewable energy power supply is greatly affected by the outside world and that it is difficult to provide continuous and stable power supply during peak and trough electricity consumption. It improves energy utilization, enhances the stability of the power supply system, and provides a green, environmentally friendly, sustainable and healthy cycle path.

[0007] In a first aspect, the present invention provides a hydrogen production and power generation system that utilizes light energy and hydrogen energy in an efficient coupling manner, and a gas power generation system that utilizes renewable energy in an efficient coupling manner, characterized in that it comprises: a renewable energy supply unit, a heat storage and exchange unit, a fuel gas supply unit, and a power generation unit;

[0008] a heat storage and exchange unit, which stores heat from renewable energy and exchanges heat with the fuel gas supply unit and / or the power generation unit;

[0009] Fuel gas supply unit, which uses renewable energy to prepare and store fuel gas;

[0010] The power generation unit includes a SOFC cell and an induction coil. The SOFC cell receives the fuel gas to react and generate electricity. The induction coil is arranged around the SOFC cell. At least when the SOFC cell is started, power is supplied to the induction coil to quickly heat up and start the SOFC cell.

[0011] Renewable energy sources include solar energy, hydropower, wind power, biomass energy, wave energy, tidal energy, ocean thermal energy, and geothermal energy. They are naturally recyclable and inexhaustible, automatically regenerating without human intervention.

[0012] The fuel gas supply unit prepares a wide variety of fuel gases, mainly fuel gases that can be provided to SOFC cells for reaction and power generation, including but not limited to hydrogen, natural gas, synthesis gas, biomass gas, etc.

[0013] Preferably, the renewable energy providing unit includes a solar thermal device to provide electrical energy and thermal energy;

[0014] Heat storage and exchange unit, storing solar heat;

[0015] The fuel gas supply unit includes a hydrogen production device that uses solar energy to convert water vapor into hydrogen and oxygen, which are stored in hydrogen and oxygen storage tanks respectively;

[0016] The anode air inlet pipe of the SOFC cell is connected to the hydrogen storage tank, and the cathode air inlet pipe is connected to the oxygen storage tank;

[0017] The power generation unit also includes a gas turbine, which includes a combustion chamber, a steam turbine and a generator. The combustion chamber is connected to the anode exhaust pipe and the cathode exhaust pipe of the SOFC cell. The steam outlet of the combustion chamber is connected to the steam turbine. The steam turbine and the generator are connected by a transmission shaft. The generator provides electrical energy to the outside and supplies power to the induction coil at least when the SOFC cell is started.

[0018] The coordinated integration of solar thermal equipment, heat storage and exchange units, hydrogen production equipment, and power generation units allows full utilization of renewable clean solar energy. This not only directly supplies power, but also uses the electricity and heat it provides to drive the operation and energy storage of other units in the system. During peak hours, the power generation unit can be used to supplement power, and under changing environmental conditions, power generation units can be switched to ensure continuous power supply. In particular, the rapid heating of the induction coil, which utilizes the electromagnetic induction principle and is powered by a gas turbine generator, effectively addresses the long startup time of SOFC cells without grid support, significantly reducing the SOFC's startup response time. This intelligent and flexible combination of multiple power generation methods provides a more stable and controllable continuous power generation system.

[0019] Preferably, the SOFC battery comprises a cylindrical battery box, and a battery pack having a plurality of SOFC battery cells, an anode gas inlet pipe, a cathode gas inlet pipe, a first current splitter, a second current splitter, an anode current collector, an anode exhaust pipe, a cathode current collector and a cathode exhaust pipe housed in the cylindrical battery box;

[0020] The anode air inlet pipe passes hydrogen into the anode of the battery unit through the first splitter, and the cathode air inlet pipe passes oxygen into the cathode of the battery unit through the second splitter;

[0021] The anode exhaust of the battery unit is passed into the anode exhaust pipe through the anode current collector, and the cathode exhaust is passed into the cathode exhaust pipe through the cathode current collector. The anode exhaust pipe is connected to the anode air inlet pipe for heat exchange, and the cathode exhaust pipe is connected to the cathode air inlet pipe for heat exchange.

[0022] Preferably, a plurality of the battery packs are arranged in the space around the anode air intake duct, each battery pack being formed into a columnar structure by stacking a plurality of battery cells, wherein the battery cells include a stacked anode side connecting plate, an anode functional layer, an electrolyte layer, a cathode functional layer and a cathode side connecting plate;

[0023] The induction coils are arranged around the columnar structure of each battery pack and are respectively connected to the generator of the gas turbine.

[0024] A cylindrical battery box is used, and the anode air intake duct and the anode exhaust duct are extended along the central axis to form a circumferentially uniform air supply and collection structure. The cathode exhaust duct and the cathode air intake duct are stacked on the inner wall of the battery box, thereby forming a space for accommodating the battery pack between the central axis formed by the anode air intake duct and the anode exhaust duct and the wall surface where the cathode exhaust duct and the air intake duct are stacked. This can form a compact solid oxide fuel cell system arrangement and reduce the system's footprint. Among them, on the inner wall of the battery box, the relatively low-temperature cathode air intake duct is preferably arranged on the outside, while the high-temperature cathode exhaust duct is arranged on the inside of the air intake duct, so that the system is less affected by external heat radiation. It can be seen that the anode air inlet pipe of the present invention is connected to the hydrogen storage tank, and the cathode air inlet pipe is connected to the oxygen storage tank. The anode air inlet pipe and the cathode air inlet pipe are connected to the molten salt (temperature is about 200°C to 500°C) storage tank for heat exchange, which can provide high-temperature hydrogen and oxygen to the SOFC. After that, the high-temperature hydrogen and oxygen enter the cylindrical battery box, and can be further heat-exchanged with the high-temperature exhaust (about 600-700°C) to increase the temperature.

[0025] More preferably, the stacking surfaces of the anode exhaust duct and the anode air intake duct, and the stacking surfaces of the cathode exhaust duct and the cathode air intake duct are both corrugated heat exchange structures, which include metal corrugated plates with a thickness of 50-500 μm, preferably 100-200 μm, to enhance heat transfer efficiency while ensuring basic mechanical strength. Compared with flat heat exchange structures, corrugated heat exchange structures are more conducive to increasing the heat exchange area and improving heat exchange efficiency. At the same time, the corrugated heat exchange structure also helps to reduce the flow resistance inside the pipeline and reduce unnecessary energy loss. In addition, the structure also has excellent mechanical support performance, ensuring the stable operation and long service life of the pipeline.

[0026] Preferably, the combustion chamber may include an air inlet, a first air inlet, a second air inlet and a steam outlet, the air inlet of the combustion chamber is connected to the external environment, the first air inlet is connected to the anode exhaust pipe of the SOFC cell, the second air inlet is connected to the cathode exhaust pipe of the SOFC cell, the steam outlet is connected to the steam turbine, and the steam turbine and the generator are connected by a transmission shaft; the generator provides electrical energy to the outside, and at least when the SOFC cell is started, supplies power to the induction coil, so that the SOFC cell quickly heats up and starts.

[0027] Preferably, the solar electric thermal device includes a solar energy conversion module, a control energy storage module and an electric heater:

[0028] (1) Solar energy conversion modules, including arrays of photovoltaic cells arranged in series to enhance voltage output;

[0029] (2) Control energy storage module, including high-frequency charging controller, battery energy storage unit and embedded microcontroller, specifically:

[0030] a high-frequency charge controller for managing electrical energy from the solar conversion module;

[0031] A battery energy storage unit for storing the aforementioned managed electrical energy;

[0032] an embedded microcontroller configured to collect data from the high-frequency charge controller and the battery energy storage unit and to monitor the high-frequency charge controller and the battery energy storage unit;

[0033] The high-frequency charging controller preferably includes a pulse width controller and a maximum power point tracking controller, which are used to optimize the charging efficiency of the battery energy storage unit, prevent overcharging and overheating of the battery energy storage unit, and extend the service life.

[0034] Pulse-width controllers (PWMs) play a vital role in solar energy systems and are a key factor influencing battery health and life. They manage and effectively regulate the flow of energy from solar panels to batteries. The core operating principle of a PWM revolves around controlling the width of the charging pulse. Specifically, a PWM can intermittently interrupt and restart the charging process. This dynamic control method allows it to effectively regulate the energy delivered to the battery, maintaining a relatively constant output voltage and preventing overcharging.

[0035] A maximum power point tracking (MPPT) controller continuously tracks and adjusts the electrical operating point of connected solar panels, dynamically adjusting the panels' electrical operating point to maximize power output and ensure the system operates at peak efficiency. By actively adapting to fluctuations in solar irradiance, the MPPT controller extracts more energy from the panels, ultimately improving overall system efficiency, regardless of changes in sunlight intensity, temperature, or shadows.

[0036] (3) An electric heater, which utilizes the electric energy of the battery energy storage unit to provide heat energy to at least the molten salt heat storage and exchange device, so as to convert the cold molten salt into hot molten salt.

[0037] The basic principle of solar power generation is based on the photovoltaic effect: when light strikes a semiconductor material, the energy from the photons excites electrons, releasing them from atoms and forming electron-hole pairs. These electrons and holes, under the influence of an electric field, migrate toward the opposite poles, generating an electric current. Solar cells utilize this effect to convert solar energy into electrical energy. The operation of solar cells involves the photovoltaic effect of a semiconductor PN junction. When sunlight or other light sources strike a semiconductor PN junction, a voltage is generated across the junction, known as the photovoltage. This voltage can be used to generate current and power external circuits.

[0038] This invention combines solar thermal equipment in a sunlight field with hydrogen production equipment and heat storage and exchange units to maximize solar energy conversion into electricity and heat. This energy is then supplied to various components of the system, while also being stored through energy conversion. Compared to traditional solar panels, this device boasts higher energy conversion efficiency, fully utilizing solar resources to achieve efficient electricity and heat supply.

[0039] Preferably, the heat storage and exchange unit includes a molten salt heat storage and exchange device, which includes a first molten salt heat exchanger for the hydrogen production equipment and a second molten salt heat exchanger for the power generation unit;

[0040] The hot molten salt and the water inlet of the hydrogen production equipment are exchanged in the first molten salt heat exchanger to obtain high-temperature water vapor, and the cooled cold molten salt is refluxed for recycling;

[0041] The hot molten salt is exchanged with the anode air and cathode air of the SOFC battery in the second molten salt heat exchanger to obtain high-temperature hydrogen and oxygen, and the cooled cold molten salt is refluxed for recycling.

[0042] Solar energy is a clean, renewable energy source. Among all renewable energy sources, it is the most widely distributed and easily accessible. However, solar energy is subject to regular variations in geography, daytime, and seasons, as well as random factors such as weather conditions. Consequently, its energy flux density is low, typically less than one kilowatt per square meter. Furthermore, energy is unstable and discontinuous over time and with changing weather. Using solar thermal storage technology to store solar energy as heat can mitigate the low energy flux density and constraints imposed by factors such as daytime, seasons, and weather conditions.

[0043] Solar thermal storage technologies include phase change storage, sensible heat storage, chemical reaction storage and other methods.

[0044] Phase change storage is the process of storing heat by utilizing a heat storage material to undergo a phase change under the influence of heat. Phase change storage offers advantages such as high energy storage density and a narrow temperature fluctuation range during the exothermic process. The present invention preferably utilizes phase change heat storage, utilizing high-temperature steam, molten salts, metals and alloys, fluoride salts and their eutectic mixtures, as well as organic phase change materials such as alcohols, acids, esters, and higher alkanes. In the solar thermal power generation and heat storage system of the present invention, molten salts are preferably, but not limited to, used as the heat storage medium, as they have advantages such as a wide temperature range, high heat capacity, low viscosity, and good chemical stability.

[0045] In addition, sensible heat storage and chemical reaction storage are also optional. Sensible heat storage is a process of storing or releasing heat by increasing or decreasing the temperature of a heat storage material using the heat capacity of the material. The heat storage principle is simple, the material source is abundant, and the cost is low, but the heat release process cannot be kept constant, and the heat storage density is low, which makes the heat storage device bulky. In addition, there is a temperature difference with the surrounding environment, resulting in heat loss. Heat cannot be stored for a long time and is not suitable for long-term, large-capacity heat storage. Chemical reaction storage uses the reaction heat of a chemical reaction to store heat. It has the advantages of high energy storage density and long-term storage, but it has high requirements for chemical reactions, product storage, and reactant toxicity.

[0046] Preferably, the hydrogen production equipment includes a SOEC hydrogen production device, which uses the electricity provided by the solar electrothermal device and the high-temperature water vapor obtained by heat exchange with the molten salt heat storage and exchange device to produce hydrogen and oxygen through electrochemical reaction, and store them in hydrogen storage tanks and oxygen storage tanks respectively;

[0047] The hydrogen production and power generation system also includes a SOEC electrolysis unit, which uses the electricity provided by the solar thermal equipment and high-temperature CO2 to produce CO and oxygen through electrochemical reactions, which are stored in exhaust gas storage tanks and oxygen storage tanks respectively;

[0048] The molten salt heat storage and exchange device includes a third molten salt heat exchanger for the SOEC electrolysis unit. The CO2 inlet gas exchanges heat with the hot molten salt in the third molten salt heat exchanger to obtain the high-temperature CO2, and the cooled molten salt is refluxed for recycling;

[0049] The CO2 intake comes from a CO2 storage tank, which is connected to the exhaust gas outlet of the gas turbine.

[0050] Hydrogen production equipment is a device that decomposes water into hydrogen and oxygen, and mainly includes three types: alkaline electrolyzers (AEC / ALK), proton exchange membrane electrolyzers (PEMEC), and solid oxide electrolyzers (SOEC). In comparison, alkaline electrolyzers are low-cost and suitable for large-scale hydrogen production; proton exchange membrane electrolyzers have fast startup and high efficiency, but are relatively expensive; solid oxide electrolyzers have the highest efficiency, but relatively high cost and maintenance fees. The present invention preferably, but not limited to, uses a SOEC hydrogen production device, utilizing solar energy, an important renewable energy source, to reduce the operating costs of the SOEC while ensuring high-efficiency hydrogen production, providing an effective solution for clean energy conversion.

[0051] Preferably, the SOFC cell is a medium-temperature solid oxide fuel cell with an operating temperature range of 600-750°C, and the exhaust gas storage tank of the SOEC electrolysis unit is connected to the anode air inlet pipe of the SOFC cell to supply electricity to the power generation unit; and / or

[0052] The exhaust gas storage tank of the SOEC electrolysis unit and the hydrogen storage tank of the SOEC hydrogen production device are both connected to the methane synthesis device; and / or

[0053] The exhaust gas storage tank of the SOEC electrolysis unit and the hydrogen storage tank of the SOEC hydrogen production device are both connected to the methanol synthesis device.

[0054] During operation, the SOFC cells in the power generation unit of the present invention generate high-temperature anode and cathode exhaust gases. In the combined power generation device of the present invention, the high-temperature SOFC exhaust gases are first used to heat exchange and heat the hydrogen and oxygen entering the SOFC, thereby improving the SOFC's power generation efficiency. The anode and cathode exhaust gases, which have been cooled by heat exchange, are then passed into the combustion chamber of a gas turbine. Unreacted feed gas and air introduced through the air inlet are combusted in the combustion chamber to produce high-temperature steam. This high-temperature steam enters the steam turbine through the steam outlet, driving the turbine to rotate. This high-temperature steam then drives the generator to output AC electricity via a drive shaft, thus fully utilizing the high-temperature exhaust gases. Simultaneously, the gas turbine produces large amounts of high-temperature CO2 and water vapor. After heat exchange with the outside and separation in a separator, the high-temperature CO2 and water vapor can be stored separately and co-extruded into the SOEC for use. The CO2, as a raw material, is heated by heat exchange with molten salt before being passed into the SOEC electrolysis unit. Through efficient electrochemical reactions, the CO2 is converted into carbon monoxide (exhaust storage tank) and oxygen (oxygen storage tank), achieving resource utilization of the CO2 and achieving energy conservation and emission reduction. CO2 can also be converted into valuable chemical raw materials, further improving the energy efficiency of the system.

[0055] Furthermore, CO stored in the exhaust gas storage tank is also an important fuel and chemical feedstock. The SOFC cell of the present invention is a medium-temperature solid oxide fuel cell with an operating temperature range of 600-750°C. The CO in the exhaust gas storage tank can be connected to the anode air inlet pipe of the SOFC cell to supply power to the power generation unit; and / or to the hydrogen storage tank of the SOEC hydrogen production unit to connect to the methane synthesis unit; and / or to the methanol synthesis unit.

[0056] Preferably, the SOFC cell includes at least one of the following:

[0057] (1) The anode-side connecting plate has a first convex rib and a first fluid groove on at least one side facing the anode, and a Cr volatilization-proof coating is provided on at least the surface of the first convex rib;

[0058] (2) The cathode-side connecting plate has a second convex rib and a second fluid groove on at least one side facing the cathode, and a Cr volatilization-proof coating is provided on at least the surface of the second convex rib;

[0059] (3) The electrolyte layer includes a three-layer structure of BCSCuO / SDC / PSDC, with BCSCuO connected to the anode functional layer and PSDC connected to the cathode functional layer;

[0060] (4) the anode functional layer comprises NiO-BCSCuO;

[0061] (5) The cathode functional layer comprises LSM-SDC or LSCF-SDC.

[0062] When arranged between two battery cells, the anode side connecting plate and the cathode side connecting plate can actually be a connecting plate assembly, with ribs and fluid grooves respectively arranged on both sides of the connecting plate assembly. At this time, the two sides of the connecting plate assembly are divided into the anode side and the cathode side.

[0063] The anode side connecting plate, cathode side connecting plate and the aforementioned connecting plate assembly can be made of ferritic stainless steel (FSS) or Fe-Cr alloy (such as Crofer-22 APU or Crofer-22HCr). The material of the anti-Cr volatilization coating can be selected from rare earth metal (Y, La, Ce, Hf, etc.) oxide materials, perovskite oxide materials (LaCoO3, LaCaCoO3, La 1-x Sr x CoO3、La 1- x Sr x MnO3, etc.), spinel oxides ((MnCo)3O4, (MnNi)3O4, MnCr2O4, NiFe2O4, etc.) to improve its oxidation resistance. Among them, it is more preferred to use SUS430 ferritic stainless steel to make the aforementioned connecting plate, and use magnetron sputtering to deposit a NiFe2 coating on its surface for 1-3h to obtain a thickness of about 0.5-4mm. The coating is sintered in an oxidizing environment of 800±20℃ to form a three-layer structure, from top to bottom Fe2O3-NiFe2O4-NiO, and the coating is a dense coating with closed pores. More preferably, in order to prevent the diffusion of elements between the aforementioned coating and the connecting plate substrate, it is more preferred to prepare a CrN diffusion prevention layer on the SUS430 ferritic stainless steel in advance, and then deposit NiFe2, and obtain Fe2O3-NiFe2O4-NiO-CrN through oxidation sintering at 800±20℃. The coating exhibits better oxidation resistance and Cr resistance, and is also beneficial to reducing the area specific resistance ASR.

[0064] Regarding the material and structure of the electrolyte layer. First, in a medium-temperature solid oxide fuel cell with an operating temperature range of 600-750°C, SDC is used as the solid electrolyte layer, and its oxygen ion conductivity is improved by about an order of magnitude compared to the existing common YSZ. In addition, in order to prevent or reduce the occurrence of electron conduction in the SDC solid electrolyte layer under reducing conditions, which leads to the occurrence of electron leakage current, and thus leads to a decrease in the fuel efficiency and energy efficiency of the entire device, the present invention forms a BCSCuO anode barrier layer on the anode side to block the electron current in the electrolyte. Compared with forming a YSZ barrier layer on the SDC layer, the BCSCuO / SDC combination has a denser structure and a more suitable thermal expansion coefficient.

[0065] The specific production process includes: Based on Ce 0.8 Sm 0.2 O 1.9(SDC) is a supporting electrolyte layer of ceria. A continuous and dense anode barrier layer is formed on one side, and a continuous and dense cathode modification layer is formed on the other side. The anode barrier layer is made of a material based on barium cerate, doped with samarium and copper. 0.8 Sm 0.19 Cu 0.1 O3 (BCSCuO), applied to the SDC electrolyte layer by electrophoretic deposition and sintered at a temperature of 1500-1550 ° C for 4-6 hours. The cathode modification layer is made of a cerium oxide material based on doped samarium and praseodymium, with a composition of Ce 0.8 (Sm 0.5 Pr 0.5 ) 0.2 O 1.9 (PSDC) was electrophoretically deposited onto the SDC electrolyte layer and sintered at 1400-1550 °C for 4-6 hours.

[0066] Based on the design of the electrolyte layer, the SOFC cell of the present invention is provided with corresponding anode functional layer and cathode functional layer. Preferably, the anode functional layer comprises NiO-BaCe with a thickness of 10-30 μm. 0.8 Sm 0.19 Cu 0.1 O3, NiO and BaCe 0.8 Sm 0.19 Cu 0.1 The mass ratio of O3 is (50-55): (45-50). The cathode functional layer preferably includes (La 0.8 Sr 0.2 ) 0.98 MnO3(LSM)-SDC or La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O3(LSCF)-SDC, wherein the mass ratio of LSM or LSCF to SDC is (55-65):(35-45).

[0067] Preferably, the SOEC hydrogen production stack of the SOEC hydrogen production device and the SOEC stack of the SOEC electrolysis unit are proton-conducting solid oxide electrolysis cells with an operating temperature of 400° C. to 800° C.;

[0068] In the SOEC hydrogen production device, the high-temperature hydrogen and oxygen generated by the reaction are respectively connected to the inlet water through the inlet water heat exchanger, and the inlet water heat exchanger is upstream of the second molten salt heat exchanger;

[0069] In the SOEC electrolysis unit, the high-temperature CO and oxygen generated by the reaction are connected to the CO2 intake through an intake heat exchanger, which is upstream of the third molten salt heat exchanger.

[0070] By utilizing exhaust waste heat and molten salt to preheat the incoming water and air, this structure effectively achieves multi-stage recycling of thermal energy, significantly reducing the electrical energy required for the electrolysis process and improving the overall efficiency and stability of the system. This design makes the present invention more efficient in terms of clean energy utilization, energy conservation, and emission reduction, maximizing the use of thermal energy resources.

[0071] In a second aspect, the present invention further provides a power generation method of the hydrogen production power generation system, including a direct power supply mode of renewable energy and a supplementary power supply mode of a power generation unit;

[0072] (1) Direct power supply mode from renewable energy, including:

[0073] The renewable energy supply unit directly supplies power to the outside and the fuel gas supply unit, and at the same time provides heat energy to the heat storage and exchange unit;

[0074] Fuel gas supply unit, which uses renewable energy to prepare and store fuel gas;

[0075] (2) Supplementary power supply mode of power generation unit, including:

[0076] The SOFC cell receives the fuel gas to react and generate electricity;

[0077] Among them, the control unit of the gas power generation system determines whether to use the power generation unit in combination or switch the power generation unit to supplement the power supply mode according to the power supply situation of the direct power supply mode of renewable energy, and at least when the SOFC cell is started, supplies power to the induction coil arranged around the SOFC cell to make the SOFC cell heat up quickly and start.

[0078] Specifically, preferably, the fuel gas supply unit includes a hydrogen production device, and the renewable energy direct power supply mode is a solar thermal device that directly supplies power to the outside and the hydrogen production unit, while providing heat energy to the heat storage and exchange unit;

[0079] The hydrogen production unit converts water vapor into hydrogen and oxygen, which are stored in hydrogen and oxygen storage tanks respectively;

[0080] In the supplementary power supply mode of the power generation unit, hydrogen from the hydrogen storage tank is introduced into the SOFC cell through the anode air inlet pipe, and oxygen from the oxygen storage tank is introduced into the SOFC cell through the cathode air inlet pipe. The high-temperature hydrogen and oxygen react chemically in the SOFC cell to output electrical energy.

[0081] The power generation unit also includes a gas turbine, which includes a combustion chamber, a steam turbine and a generator. The anode exhaust and cathode exhaust of the SOFC cell enter the combustion chamber and burn to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the drive shaft. At least when the SOFC cell is started, the gas turbine supplies power to the induction coil, causing the SOFC cell to quickly heat up and start.

[0082] Preferably, the SOFC battery rapid temperature rise start-up comprises the following steps:

[0083] S1: The hydrogen in the hydrogen storage tank and the oxygen in the oxygen storage tank are preheated by heat storage and heat exchange units to preheat the SOFC battery pack. After that, the hydrogen enters the combustion chamber through the anode exhaust pipe and the cathode exhaust pipe respectively to burn and generate high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft;

[0084] S2. The generator supplies power to the induction coil surrounding the SOFC cells, rapidly heating the cell stack to 600°C to 750°C.

[0085] For faster startup, the induction coil can also be activated using or supplemented with other external AC power supplies or the grid. Furthermore, based on power consumption monitoring data or empirical data, pre-heating the SOFC cells by using AC power converted from solar thermal equipment to power the induction coil is also an option. However, if the aforementioned power supply methods are inconvenient or insufficient, or in certain emergencies, utilizing the power generation unit's gas turbine can provide a basic guarantee for rapid startup. This underscores the importance and necessity of including a gas turbine in addition to the solar thermal equipment and SOFC cells in this invention.

[0086] Preferably, the direct power supply mode also includes a gas turbine exhaust gas utilization process:

[0087] The SOEC stack of the SOEC electrolysis unit utilizes the electricity provided by the solar thermal device and the high-temperature CO2 obtained by heat exchange with the hot molten salt provided by the gas turbine to produce carbon monoxide and oxygen through electrochemical reaction, which are output through the exhaust pipe and the oxygen outlet pipe and stored in the exhaust storage tank and the oxygen storage tank respectively;

[0088] Optionally, in the power generation unit supplementary power supply mode, the exhaust gas storage tank is connected to the anode air inlet pipe of the SOFC cell to supply power to the power generation unit; and / or

[0089] The exhaust gas storage tank and the hydrogen storage tank are both connected to a methane synthesis device to react and generate methane; and / or the exhaust gas storage tank and the hydrogen storage tank are both connected to a methanol synthesis device to catalytically generate methanol.

[0090] The present invention has at least the following beneficial effects:

[0091] (1) The present invention achieves efficient conversion and utilization of renewable energy, including electrical energy, thermal energy, and chemical energy, by organically combining a renewable energy supply unit, a heat storage and exchange unit, a fuel gas supply unit, and a power generation unit. In particular, the solar thermal device converts light energy into electrical energy and thermal energy, the heat storage and exchange unit effectively stores thermal energy, the hydrogen production device efficiently converts electrical energy and thermal energy into hydrogen and oxygen, and the power generation unit efficiently converts hydrogen and other fuel gases into electrical energy. Furthermore, the converted hydrogen and other fuel gases and oxygen can be separately utilized or sold. The entire system forms an efficient multi-energy conversion path, maximizing energy utilization.

[0092] (2) The continuous power generation system using clean energy of the present invention combines direct power supply from renewable energy with supplementary power supply from power generation units, and can be flexibly adjusted according to changes in the external environment and power supply demand. Among them, when the supply of renewable energy is sufficient, the system mainly uses renewable energy to supply power to the external and internal units, and at the same time, the fuel gas is pre-prepared or integrated through the fuel gas supply unit and stored accordingly; when the renewable energy is insufficient, or the power consumption increases sharply, the system automatically switches to the supplementary power supply mode of the power generation unit, or starts the supplementary power supply mode of the power generation unit to supplement the direct power supply mode, to ensure the continuity and sufficiency of the power supply. This flexible and diversified power supply mode greatly improves the stability and reliability of the system, and ensures the ability to maintain continuous and stable power supply under a variety of external environments, conditions and power demands.

[0093] (3) The heat storage and exchange unit and multi-stage heat exchange method play an important role in the entire system, effectively reducing heat loss and ensuring efficient energy transfer between the various units within the system. In particular, in terms of preheating the raw materials in the fuel gas supply unit and the power generation unit, energy loss is further reduced, significantly improving the efficiency of the entire system. In particular, the gas turbine generator is used to provide AC power to the induction coil. While preheating the high-temperature raw gas, the temperature of the battery pack is quickly raised to the operating temperature, overcoming the problems of slow startup and high energy consumption of solid oxide fuel cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 This is a connection diagram of the hydrogen production and power generation system of the present invention.

[0095] Reference numerals:

[0096] 1-Solar electric thermal equipment, 211-Hot molten salt storage tank, 212-Cold molten salt storage tank, 221-First molten salt heat exchanger, 222-Second molten salt heat exchanger, 223-Third molten salt heat exchanger, 3-SOEC hydrogen production device, 4-SOEC electrolysis unit, 51-SOFC battery, 52-Induction coil, 531-Combustion chamber, 5311-Air inlet, 5312-First air inlet, 5313-Second air inlet, 532-Steam turbine, 533-Generator, 6-Water storage tank, 7-Hydrogen storage tank, 8-Oxygen storage tank, 9-Exhaust storage tank, 10-Separator. DETAILED DESCRIPTION

[0097] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the specification and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0098] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a," "an," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, and unless the context clearly indicates otherwise, "a plurality" generally includes at least two.

[0099] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or device. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or device comprising the element.

[0100] like Figure 1 As shown, the present invention provides a gas power generation system that utilizes renewable energy for efficient coupling, comprising: a renewable energy supply unit, a heat storage and exchange unit, a hydrogen production device, a power generation unit, and an optional SOEC electrolysis unit 4;

[0101] (1) The renewable energy providing unit is preferably, but not limited to, a solar electric thermal device 1, including a solar energy conversion module, a control energy storage module, and an electric heater:

[0102] (1.1) Solar energy conversion modules, including photovoltaic cell arrays arranged in series, convert solar energy into electrical energy and increase voltage output. The photovoltaic cell array can use high-efficiency single-crystal silicon or polycrystalline silicon solar cells to ensure maximum absorption of solar light.

[0103] (1.2) Control energy storage module, including high-frequency charging controller, battery energy storage unit and embedded microcontroller, specifically:

[0104] a high-frequency charge controller for managing electrical energy from the solar conversion module;

[0105] A battery energy storage unit for storing the aforementioned managed electrical energy;

[0106] an embedded microcontroller configured to collect data from the high-frequency charge controller and the battery energy storage unit and to monitor the high-frequency charge controller and the battery energy storage unit;

[0107] The high-frequency charging controller preferably includes a pulse width controller and a maximum power point tracking controller to optimize the charging efficiency of the battery energy storage unit, prevent overcharging and overheating, and extend the battery energy storage unit's service life. All of these components can be commercially available.

[0108] (1.3) The electric heater uses the electric energy of the battery energy storage unit to provide heat energy to at least the molten salt heat storage and exchange device. The cold molten salt in the cold molten salt storage tank 212 is pumped to the electric heater, absorbs the heat energy and converts it into hot molten salt, which is stored in the hot molten salt storage tank 211.

[0109] (2) a heat storage and exchange unit, preferably but not limited to a molten salt heat storage and exchange device, comprising a first molten salt heat exchanger 221 for a hydrogen production device, a second molten salt heat exchanger 222 for a power generation unit, and a third molten salt heat exchanger for an SOEC electrolysis unit 4, wherein the first molten salt heat exchanger 221, the second molten salt heat exchanger 222 and the third molten salt heat exchanger 223 are respectively connected to the cold molten salt storage tank 212 and the hot molten salt storage tank 211 by pipeline;

[0110] The hot molten salt output from the hot molten salt storage tank 211 exchanges heat with the water inlet of the hydrogen production equipment in the first molten salt heat exchanger 221, and the high-temperature water vapor is passed into the SOEC hydrogen production stack. The cooled cold molten salt flows back to the cold molten salt storage tank 212 for recycling;

[0111] The hot molten salt output from the hot molten salt storage tank exchanges heat with the anode air and cathode air of the SOFC cell 51 in the second molten salt heat exchanger 222, providing high-temperature hydrogen and oxygen to the SOFC cell 51, and the cooled cold molten salt flows back to the cold molten salt storage tank 212 for recycling;

[0112] The hot molten salt output from the hot molten salt storage tank 211 exchanges heat with the CO2 inlet gas of the SOEC electrolysis unit 4, providing high-temperature CO2 to the SOEC electrolysis unit 4, and the cooled cold molten salt flows back to the cold molten salt storage tank 212 for recycling;

[0113] (3) A fuel gas supply unit, including a hydrogen production device, preferably but not limited to a SOEC hydrogen production device 3, including a SOEC hydrogen production stack, a water inlet pipe and a water storage tank 6, a hydrogen outlet pipe and a hydrogen storage tank 7, an oxygen outlet pipe and an oxygen storage tank 8. The SOEC hydrogen production stack is a proton-conducting solid oxide electrolysis cell with an operating temperature of 400°C to 800°C. The water inlet pipe is first connected to the hydrogen outlet pipe and the oxygen outlet pipe for heat exchange, and then the water inlet pipe is further connected to the hot molten salt storage tank 211 for heat exchange. The high-temperature water vapor obtained by heat exchange is converted into hydrogen and oxygen through electrochemical reaction, which are output from the hydrogen outlet pipe and the oxygen outlet pipe and stored in the hydrogen storage tank 7 and the oxygen storage tank 8, respectively.

[0114] (4) SOEC electrolysis unit 4, including SOEC stack, CO2 inlet pipe and CO2 gas tank, exhaust pipe and exhaust storage tank 9, oxygen outlet pipe, the SOEC stack is a proton conduction solid oxide electrolysis cell, and the operating temperature is 400°C to 800°C. The oxygen outlet pipe is connected to the oxygen storage tank 8 of the SOEC hydrogen production device 3, the CO2 gas tank is connected to the exhaust gas outlet of the gas turbine, the inlet pipe is first connected to the exhaust pipe and the oxygen outlet pipe for heat exchange, and then the inlet pipe is connected to the hot molten salt storage tank 211 through the third molten salt heat exchanger for heat exchange. The high-temperature CO2 obtained by heat exchange is converted into carbon monoxide and oxygen through electrochemical reaction, which are output from the exhaust pipe and the oxygen outlet pipe and stored in the exhaust storage tank 9 and the oxygen storage tank 8 respectively.

[0115] In addition to being used as feed gas for SOFC, the CO in the exhaust gas storage tank 9 of the SOEC electrolysis unit 4 and the hydrogen in the hydrogen storage tank 7 of the SOEC hydrogen production device 3 can be used for other synthetic purposes to obtain green and high-value products, including but not limited to:

[0116] The exhaust gas storage tank 9 of the SOEC electrolysis unit 4 and the hydrogen storage tank 7 of the SOEC hydrogen production device 3 are both connected to the methane synthesis device; and / or

[0117] The exhaust gas storage tank 9 of the SOEC electrolysis unit 4 and the hydrogen storage tank 7 of the SOEC hydrogen production device 3 are both connected to the methanol synthesis device.

[0118] (5) Power generation unit, including SOFC cell 51, induction coil 52 and gas turbine:

[0119] (5.1) SOFC cell 51, SOFC cell 51 includes a cylindrical cell box, and a cell stack having a plurality of SOFC cells 51, an anode gas inlet pipe, a cathode gas inlet pipe, a first splitter, a second splitter, an anode current collector, an anode exhaust pipe, a cathode current collector, and a cathode exhaust pipe housed in the cylindrical cell box.

[0120] The anode air inlet pipe passes hydrogen into the anode of the battery unit through the first splitter, and the cathode air inlet pipe passes oxygen into the cathode of the battery unit through the second splitter; the anode exhaust of the battery unit passes into the anode exhaust pipe through the anode current collector, and the cathode exhaust passes into the cathode exhaust pipe through the cathode current collector; inside the cylindrical battery box, the anode exhaust pipe is connected to the anode air inlet pipe for heat exchange, and the cathode exhaust pipe is connected to the cathode air inlet pipe for heat exchange.

[0121] Outside the cylindrical battery box, the anode air inlet pipe is connected to the hydrogen storage tank 7, and the cathode air inlet pipe is connected to the oxygen storage tank 8. The anode air inlet pipe and the cathode air inlet pipe are connected to the hot molten salt storage tank 211 for heat exchange to provide high-temperature hydrogen and oxygen.

[0122] A plurality of battery packs are arranged in the space around the anode air intake pipe. Each battery pack is formed into a columnar structure by stacking a plurality of battery cells. The battery cells include stacked anode side connecting plates, anode functional layers, electrolyte layers, cathode functional layers and cathode side connecting plates.

[0123] The SOFC cell 51 of the present invention uses a medium-temperature solid oxide fuel cell with an operating temperature range of 600-750°C. The feed gas provided to the anode air inlet pipe can come from the hydrogen provided by the hydrogen storage tank 7 and the CO provided by the exhaust gas storage tank 9. This is also an important advantage of the medium-temperature solid oxide fuel cell.

[0124] (5.2) The induction coil 52 is arranged around the columnar structure of each battery pack and is connected to the generator 3 of the gas turbine respectively.

[0125] (5.3) The gas turbine includes a combustion chamber 531, a steam turbine 532 and a generator 533. The combustion chamber 531 includes an air inlet 5311, a first air inlet 5312, a second air inlet 5313 and a steam outlet. The air inlet 5311 of the combustion chamber 531 is connected to the external environment and can replenish the combustion air for the combustion chamber 531. The first air inlet 5312 is connected to the anode exhaust pipe of the SOFC cell 51, the second air inlet 5313 is connected to the cathode exhaust pipe of the SOFC cell 51, and the steam outlet is connected to the steam turbine 532. The steam turbine 532 and the generator 533 are connected by a transmission shaft; the generator 533 provides electrical energy to the outside and, at least when the SOFC cell 51 is started, supplies power to the induction coil 52 to enable the SOFC cell 51 to quickly heat up and start.

[0126] At the same time, the gas turbine will produce a large amount of high-temperature CO2 and water vapor. After the high-temperature CO2 and water vapor are exchanged with the outside and separated by the separator 10, they can be stored and supplied to the SOEC hydrogen production device and SOEC electrolysis unit respectively. Among them, CO2 is used as the raw material intake gas and is passed into the SOEC electrolysis unit after heat exchange with the hot molten salt to increase the temperature. Through efficient electrochemical reactions, CO2 is converted into carbon monoxide (exhaust storage tank) and oxygen (oxygen storage tank), realizing the resource utilization of CO2 and achieving the effect of energy conservation and emission reduction. CO2 can also be converted into valuable chemical raw materials, further improving the energy utilization efficiency of the system.

[0127] Based on the above system, the present invention provides a power generation method. The system includes a direct power supply mode of renewable energy and a supplementary power supply mode of power generation units to ensure that the entire system can achieve continuous and stable power supply under different operating conditions. The specific method is as follows:

[0128] (1) Renewable energy direct power supply mode:

[0129] Solar thermal equipment directly supplies power to the external environment and the hydrogen production unit: When solar resources are sufficient, the solar thermal equipment converts light energy into electricity, providing stable power through the photovoltaic cell array. This power is directly supplied to external loads and the SOEC hydrogen production device and SOEC electrolysis unit within the system, meeting external power demand and the electricity required for internal hydrogen and CO production processes. At the same time, part of the electricity generated by the solar thermal equipment is used to heat the molten salt heat storage and exchange device, converting cold molten salt into high-temperature hot molten salt, which is stored in the hot molten salt storage tank to provide thermal energy for multiple subsequent heat exchange processes.

[0130] The SOEC hydrogen production stack of the SOEC hydrogen production device uses the electricity provided by the solar thermal equipment and the high-temperature water vapor obtained by heat exchange with molten salt to undergo an electrochemical reaction to generate high-purity hydrogen (H2) and oxygen (O2), which are stored accordingly. The SOEC stack of the SOEC electrolysis unit uses the electricity provided by the solar thermal equipment and the high-temperature CO2 obtained by heat exchange with molten salt to undergo an electrochemical reaction to generate high-purity hydrogen (CO) and oxygen (O2), which are stored accordingly. The hydrogen produced by the SOEC hydrogen production device and the CO produced by the SOEC electrolysis unit can not only be used as feed gas for the power generation unit, but can also be used as raw materials to synthesize green and high-value products, providing more energy storage methods.

[0131] (2) Supplementary power supply mode of power generation unit:

[0132] When solar energy resources are insufficient, such as at night or on cloudy days when there is no photovoltaic power, or when the power demand of the system exceeds the power supply capacity of the solar thermal equipment, the system automatically switches to the power generation unit supplementary power supply mode.

[0133] (2.1) SOFC quick start method:

[0134] S1. The high-temperature hydrogen and oxygen obtained by heat exchange with the hot molten salt are used to preheat the battery pack. Since the battery pack has not yet reached the operating temperature, the hydrogen and oxygen after heat exchange enter the combustion chamber of the gas turbine through the anode exhaust pipe and the cathode exhaust pipe respectively, and are burned to produce high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft;

[0135] S2. The generator supplies power to the induction coil connected thereto to perform induction heating on the battery pack, quickly raising the temperature of the battery pack to an operating temperature of 600° C. to 750° C., preferably within 10 minutes, more preferably within 8 minutes.

[0136] S3. Once the battery pack reaches operating temperature and is functioning normally, in addition to continuing to introduce high-temperature hydrogen and oxygen to generate electricity within the SOFC cells, CO feedstock from the SOEC electrolysis unit can also be introduced. The generator stops supplying power to the coil, and the AC power generated by the generator can be switched to other power-consuming components in the system or transmitted externally, further improving the system's power supply capacity. Cooling water is introduced into the hollow tube of the induction coil to reduce its temperature and prevent damage. The heat exchange water can be exported or recycled within the system.

[0137] Traditional thermal power plants typically have a power generation efficiency of 30% to 40%, and large-scale cogeneration plants can only achieve a thermal energy utilization rate of 60% to 70%. Development efforts have primarily focused on improving boiler performance and thermal efficiency. However, thermal power generation relies heavily on coal and oil, resulting in significant environmental pollution and a growing concern. Conventional solar photovoltaic (PV) power generation efficiency typically ranges from 15% to 45%, influenced by numerous factors, including solar radiation, temperature, and the materials and structure of the PV cells. Currently, SOEC laboratory water electrolysis efficiency approaches 100%. Conventional SOFCs (solid oxide fuel cells) achieve power generation efficiencies exceeding 60%, with low pollutant emissions, low operating costs, and excellent long-term stability. Medium-temperature solid oxide fuel cells, in particular, offer the advantage of compatibility with a variety of feed gases.

[0138] We monitored the combined thermal hydrogen and power efficiency, peak combined efficiency, and SOFC cell rapid startup time multiple times throughout the day. Average values ​​were taken, as shown in Table 1. These values ​​are for January (average value taken from the 1st to the 5th day), April (average value taken from the 1st to the 5th day), July (average value taken from the 1st to the 5th day), and October (average value taken from the 1st to the 5th day) in 2024.

[0139] Table 1

[0140] January April July October Average efficiency ＞78％ ＞80％ ＞85％ ＞80％ Maximum efficiency 98.0％ 97.5％ 99.2％ 98.4％ Average startup time / min 7.2 6.8 4.8 5.5

[0141] It can be seen that the hydrogen production and power generation system and power generation method provided by the present invention can maintain a stable thermal power and hydrogen cogeneration efficiency of more than 75% in different seasons of the year. It is based on the full utilization and storage of solar energy, adopts a SOEC hydrogen production device and a SOEC electrolysis unit for energy conversion and energy storage, and combines SOFC cells and gas turbines to quickly supplement power supply (the SOFC cell quick start time is within 8 minutes), thereby improving the utilization rate of clean energy on the basis of the system's ability to provide stable external power supply.

[0142] Although preferred embodiments of the present invention have been described, further changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are understood. Therefore, the present invention is intended to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention. Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. A gas-fired power generation system utilizing efficient coupling of renewable energy, characterized in that: include: Renewable energy supply unit, heat storage and exchange unit, fuel gas supply unit, power generation unit and SOEC electrolysis unit; Renewable energy supply units include solar thermal equipment, which provides electricity and heat; The heat storage and exchange unit includes a molten salt heat storage and exchange device, which stores the heat of solar energy and exchanges heat with the fuel gas supply unit, the power generation unit and the SOEC electrolysis unit; the molten salt heat storage and exchange device includes a first molten salt heat exchanger for the SOEC hydrogen production device of the fuel gas supply unit, a second molten salt heat exchanger for the power generation unit and a third molten salt heat exchanger for the SOEC electrolysis unit; The fuel gas supply unit uses renewable energy to prepare and store fuel gas. The fuel gas supply unit includes a SOEC hydrogen production device, which uses the electricity provided by the solar electric thermal equipment and the high-temperature water vapor obtained by heat exchange with the molten salt heat storage and exchange device to produce hydrogen and oxygen through electrochemical reactions. The hydrogen and oxygen are stored in hydrogen and oxygen storage tanks respectively. The power generation unit includes an SOFC cell and an induction coil. The SOFC cell receives the fuel gas to react and generate electricity. The induction coil is arranged around the SOFC cell. The SOFC cell is a medium-temperature solid oxide fuel cell with an operating temperature range of 600-750°C. The anode air inlet pipe of the SOFC cell is connected to the hydrogen storage tank, and the cathode air inlet pipe is connected to the oxygen storage tank. The power generation unit also includes a gas turbine, which includes a combustion chamber, a steam turbine, and a generator. The combustion chamber is connected to the anode exhaust pipe and the cathode exhaust pipe of the SOFC cell. The steam outlet of the combustion chamber is connected to the steam turbine. The steam turbine and the generator are connected by a transmission shaft. The generator provides electrical energy to the outside and, at least when the SOFC cell is started, supplies power to the induction coil to quickly heat up the SOFC cell and start it. The SOEC electrolysis unit uses electricity from solar thermal equipment and high-temperature CO2 to produce CO and oxygen through an electrochemical reaction, which are stored in exhaust and oxygen storage tanks, respectively. The exhaust storage tank is connected to the anode air inlet pipe of the SOFC cell to supply electricity to the power generation unit. The CO2 intake gas exchanges heat with the hot molten salt in the third molten salt heat exchanger to obtain the high-temperature CO2, and the cooled cold molten salt is refluxed for recycling; the CO2 intake gas comes from the CO2 gas storage tank, and the CO2 gas storage tank is connected to the exhaust gas outlet of the gas turbine.

2. The gas-fired power generation system according to claim 1, wherein: The SOFC battery comprises a cylindrical battery box, and a battery pack having a plurality of SOFC battery cells, an anode gas inlet pipe, a cathode gas inlet pipe, a first current splitter, a second current splitter, an anode current collector, an anode exhaust pipe, a cathode current collector, and a cathode exhaust pipe housed in the cylindrical battery box. The anode air inlet pipe passes hydrogen into the anode of the battery unit through the first splitter, and the cathode air inlet pipe passes oxygen into the cathode of the battery unit through the second splitter; The anode exhaust of the battery unit is passed into the anode exhaust pipe through the anode current collector, and the cathode exhaust is passed into the cathode exhaust pipe through the cathode current collector. The anode exhaust pipe is connected to the anode air inlet pipe for heat exchange, and the cathode exhaust pipe is connected to the cathode air inlet pipe for heat exchange.

3. The gas-fired power generation system according to claim 1 or 2, characterized in that: Solar electric thermal equipment includes solar energy conversion module, control energy storage module and electric heating module: (1) A solar energy conversion module comprising an array of photovoltaic cells arranged in series; (2) Control energy storage module, including high-frequency charging controller, battery energy storage unit and embedded microcontroller, among which, a high-frequency charge controller for managing electrical energy from the solar conversion module; A battery energy storage unit for storing the aforementioned managed electrical energy; an embedded microcontroller configured to collect data from the high-frequency charge controller and the battery energy storage unit and to monitor the high-frequency charge controller and the battery energy storage unit; (3) The electric heating module uses the electric energy of the battery energy storage unit to provide heat energy to at least the heat storage and exchange unit.

4. The gas-fired power generation system according to claim 3, wherein: The hot molten salt and the inlet water of the SOEC hydrogen production device are exchanged in the first molten salt heat exchanger to obtain high-temperature water vapor, and the cooled cold molten salt is refluxed for recycling; The hot molten salt is exchanged with the anode air and cathode air of the SOFC battery in the second molten salt heat exchanger to obtain high-temperature hydrogen and oxygen, and the cooled cold molten salt is refluxed for recycling.

5. The gas-fired power generation system according to claim 1 or 2, characterized in that: The exhaust gas storage tank of the SOEC electrolysis unit and the hydrogen storage tank of the SOEC hydrogen production device are both connected to the methane synthesis device.

6. The gas-fired power generation system according to claim 1 or 2, characterized in that: The exhaust gas storage tank of the SOEC electrolysis unit and the hydrogen storage tank of the SOEC hydrogen production device are both connected to the methanol synthesis device.

7. A method for generating electricity using the gas-fired power generation system according to any one of claims 1 to 6, characterized in that: Including direct power supply mode of renewable energy and supplementary power supply mode of power generation unit; (1) Renewable energy direct power supply mode, including: The renewable energy supply unit directly supplies power to the outside and the fuel gas supply unit, and at the same time provides heat energy to the heat storage and exchange unit; Fuel gas supply unit, which uses renewable energy to prepare and store fuel gas; (2) Supplementary power supply mode of power generation unit, including: The SOFC cell receives the fuel gas to react and generate electricity; Among them, the control unit of the gas power generation system determines whether to use the power generation unit in combination or switch the power generation unit to supplement the power supply mode according to the power supply situation of the direct power supply mode of renewable energy, and at least when the SOFC cell is started, supplies power to the induction coil arranged around the SOFC cell to make the SOFC cell heat up quickly and start.

8. The power generation method according to claim 7, wherein: The fuel gas supply unit includes a SOEC hydrogen production device. In the renewable energy direct power supply mode, the solar thermal equipment directly supplies power to the outside and the SOEC hydrogen production device, while also providing heat energy to the heat storage and exchange unit. The SOEC hydrogen production device converts water vapor into hydrogen and oxygen, which are stored in hydrogen and oxygen storage tanks respectively; In the supplementary power supply mode of the power generation unit, hydrogen from the hydrogen storage tank is introduced into the SOFC cell through the anode air inlet pipe, and oxygen from the oxygen storage tank is introduced into the SOFC cell through the cathode air inlet pipe. The high-temperature hydrogen and oxygen react chemically in the SOFC cell to output electrical energy. The power generation unit also includes a gas turbine, which includes a combustion chamber, a steam turbine and a generator. The anode exhaust and cathode exhaust of the SOFC cell enter the combustion chamber and burn to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the drive shaft. At least when the SOFC cell is started, the gas turbine supplies power to the induction coil, causing the SOFC cell to quickly heat up and start.

9. The power generation method according to claim 8, wherein: The SOFC battery rapid temperature rise start-up includes the following steps: S1: The hydrogen in the hydrogen storage tank and the oxygen in the oxygen storage tank are preheated by heat storage and heat exchange units to preheat the SOFC battery pack. After that, the hydrogen enters the combustion chamber through the anode exhaust pipe and the cathode exhaust pipe respectively to burn and generate high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft; S2. The generator supplies power to the induction coil surrounding the SOFC cells, rapidly heating the cell stack to 600°C to 750°C.

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